Fluid control method and apparatus



Jam 25, 1966 L. G. KITCHEN ETAL 3,230,688

FLUID CONTROL METHOD AND APPARATUS Filed June 28, 1962 INVENTORS L.G.KITCHEN J T KARBOSKY BY A TTORNEVS United States Patent O 3,230,688FLUID CONTRQL METHUD AND APPARATUS Leland G. Kitchen and Joseph T.Karbosky, Bartlesville,

Okla., assignors to Phillips Petroleum Company, a corporation ofDelaware Filed June 28, 1962, Ser. No. 205,996 13 Claims. (Cl. 55-20)This invention relates to control of a fluid system. In one of itsaspects, it relates to method and apparatus for by-passing thecirculation of heated fluid in a process in response to an abnormaloperational condition in said fluid, and for indicating the cause ofby-passing by the combination of readings of a plurality of indicators.In another aspect, the invention relates to method and apparatus forshutting down a regeneration fluid system in an adsorption process inresponse to an abnormal condition of lsaid regeneration fluid, and forindicating the cause of shut-down by the combination of readings of aplurality of indicators.

Many physical and chemical processes require as one of their steps thesupplying of heat to the process. Heat can be conveniently supplied by aheated fluid stream which is either added directly to the process orpassed in indirect heat exchange with it. However, when this heatedfluid stream exhibits some abnormal characteristic which would bedetrimental to the process, it becomes necessary to shut olf this heatsource in some manner. Further, when such a heat source has been shutolf automatically, it is often difcult to determine what abnormalcondition has effected the shut-down, thus making a re-starting of theprocess diicult or impossible until the abnormality can be corrected.

It is an object of our invention to provide method and apparatus forshutting down flow of a iuid heating stream in response to an abnormalcondition of the stream, and to indicate what condition of the streameffects the shutdown. It is another object of our invention to providemethod and apparatus for automatically stopping flow of heatedregeneration fluid to an absorption process in response to an abnormalcondition of the uid, and for indicating the abnormality after thestopping.

Other aspects, objects, and the several advantages of the invention willbecome apparent to one skilled in the art upon study of this disclosure,the drawing, and the appended claims.

According to our invention, we have discovered method and apparatus forcontrolling flow of a fluid wherein the uid passes to a Valve zone andthence when the valve zone is in a irst position to a fluid heating zoneand when the Valve zone is in a second position to a fluid heatingby-pass zone which comprises measuring flow rate of the fluid, passing amotive force to the valve zone so as to maintain the valve zone in therst position, producing a signal proportional to the flow rate inresponse to the measuring, blocking the motive force so as to cause afirst indicator zone to exhibit a first reading and a second indicatorzone to exhibit a lirst reading and to cause the valve zone to move tothe second position in response to the signal being above a firstpredetermined value, and blocking the motive force so as to cause thefirst indicator zone to exhibit a second reading and the secondindicator zone to indicate a first reading and to cause the valve zoneto move to the second position in response to the signal being below asecond predetermined value, whereby the valve zone effects by-passing ofthe heating zone by the uid when the How rate is outside the rangedefined by the first and second predetermined values and whereby thereadings of the iirst and second indicator zones indicate the cause ofthe bypassing.

In the drawing, there is represented a presently-preice ferredembodiment of our invention as applied to an adsorption process whereina pneumatically-actuated shutdown and indicator control system is used.

Referring now to the drawing, there is shown a source of -raw gasentering the system by way of conduit 1, three-way valve 2, and conduit3 to process 4. In process 4, the gas is subjected to adsorption inorder to remove natural gas liquids, and the gas is passed from theprocess after removal of these components by way of conduit 5 to furtherutility. The raw gas is normally apportioned by valve 2 between conduits3 and 6; gas flowing through the latter conduit drives fluid motor 7 andthen is passed by way of conduit 8 to be mixed with gas in conduit 3 asfeed for process 4. This adsorption process produces natural gas liquidsby regeneration of the adsorbent with a hot vapor; the resulting mixtureof regeneration fluid and raw gasoline is passed by way of conduit 9 toa vapor drum 10. A portion of the vapors in drum 10 are withdrawn by wayof conduit 11 to be returned to the process as regeneration fluid aftersuitable heating. The flow 4rate of this vapor is measured, for example,by oriiice 12 and they are pumped through the regeneration circuit by apump .13, preferably driven by fluid motor 7. Three-Way valve 14 inconduit 11 is normally positioned to pass all the vapors from pump 13 byway of conduit 15 and heater 16; when valve 14 is moved to its otherposition, heater 16 is by-passed. Heater 16 is provided with a suitablesource of heat as in conduit 17; ow therethrough is controlled by valve18. A ilow transmitter 19 senses ow in conduit 11 by pressure dropacross orice 12 and passes a signal modulated proportional to flow rateas the input to flow recorder controller 20. Transmitter 19 modulatesair received by way of conduit 21. The output of controller 20 serves toadjust valve 2 so as to proportion the ow of raw gas between motor 7 andby-pass 3. A second source of instrument air is passed by way of conduit22 to threeway valve 23; this latter valve is normally positioned (withair pressure of above l0 p.s.i.g. on its diaphragm) to pass air to thediaphragms of valve 14 and as supply air to controllers 20 and 38. Withless than 10 p.s.i.g. pressure on the diaphragm of Valve 23, the valveswitches to its second position whereby it vents the diaphragms of valve14 and discontinues the air supply to controllers 20 and 38.

A portion of the vapors in drum 1li is condensed by suitable cooling,and .the resulting raw gasoline flows by gravity into liquid accumulator24. Product gasoline is withdrawn from this vessel by way of conduit 25,controlled by valve 26 in response to liquid level controller 27 so asto maintain a suitable liquid level. A high-level switch 28 senses abovethe normal liquid level of this vessel and transmits a signal of aboutl5 p.s.i.g. to one port of three-way valve 29; when the level in vessel24 rises to the sensing point, switch 28 transmits no signal to valve29. A second port of valve 29 is connected serially to three-way valves30 and 31 as shown. The third or vented port of valve 30 is preferablysupplied with an orifice. Valve 31 also has one port vented, and itsthird port is connected through hand starter on regulator valve 32 tothe diaphragm motor of valve 23. The diaphragm motors of valves 30 and23 are connected through a check valve 33 as shown, allowing flow onlyfrom the latter to .the former. The motor of valve 30 is also connectedto the conduit communicating between valves Sil and 31. The motors ofvalves 29 and 31 are connected to the modulated output signal fromtransmitter 19. Three pressure indicators 34, 35 and 36 are provided asshown.

Valve 29 is adjusted to connect switch 28 to valve 30 when there is lessthan l2 p.s.i.g. on its motor; pressure on its motor above this valueswitches it to connect valve 30 to vent. Valve 30 is adjusted to connectvalves 29 and 31 when there is above l0 p.s.i.g. on its motor; pressureon its motor less than this value switches it to connect valve 31 tovent. Valve 31is adjusted to connect valve 14 and controllers 20 and 38.Further, this same pressure signal passes to the motor of valve 30,locking it into position. Valves 14 and 18 are now oriented so as toca-use the regeneration fluid to be superheated in valve 30 and starter32 when there is above 6 p.s.i.g. on 5 heater 16. It is noted thatpressure indicators 34, 35 its motor; pressure on its motor less thanthis value and 36 will all indicate some pressure above zeroindicatswitches it to connect starter valve 32 to vent. Flow ing normaloperation. transmitter 19 is adjusted to transmit a signal to controllerWhen for any reason the level in accumulator 24 rises 20 and thediaphragms of valves 29 and 31 of about 6-12 unduly, switch 28 no longertransmits a signal, i.e., its p.s.i.g. over the desired ow rate range;its output signal output is 0 p.s.i.g. This lack of signal immediatelyturns is accordingly less than 6 p.s.i.g. or greater than 12 p.s.i.g.valves 23 and 3l). Valve 23 accordingly vents pressure when the iiowrate in conduit 11 is less or greater .than from the motors of valve 14and controller 38, effecting the desired range. Instrument air sources21, 22 and 37 by-pass of heater 16 and shut-oftr of heat source 17.Valve are above 15 p.s.i.g., preferably around 30 p.s.i.g. 23 furthervents the air supply to controller 20, causing Temperature controller 38is operatively connected to 15 valve 2 to switch to by-pass uid motor 7,With raw gas line 11. Controller 38 receives instrument air from linepassing directly through conduit 3. Since uid motor 7 is 22 andtransmits a pneumatic signal to valve 18 to constopped, regenerationiluid pump 13 also stops. The retrol the flow of fuel gas through line17 to maintain a generation circuit has now been shut down, and raw gasconstant temperature in line 11. When valve 23 is turned passes throughprocess 4 without being treated. The outto vent, controller 38 will notreceive any instrument air 20 put of switch 28 being zero, gauge 34 willread Zero. to transmit a pneumatic signal to Valve 18 and valve 18 Valve30 being turned to vent causes gauges 35 and will close. 36 to readzero. All three gauges reading zero indicates Operation of the systemwill now be described with shut-down of the system because of high levelin liquid reference to the drawing and Table I. During normalaccumulator 24. operation of the system, raw gas enters by way ofconduit 25 When for any reason the ow rate of regeneration vapor 1 anddrives iluid motor 7 before being treated in process in conduit 11becomes excessive, i.e., above the pre-set 4 for removal of its naturalgas liquids content, for range of transmitter 19, this transmitterproduces a signal example by adsorption. Treated gas is removed forfurof above 12 p.s.i.g. Such a signal -does not effect a change ther useby way of conduit 5. The liquids removed are of position of valve 31,but does switch valve 29 so as passed (usually in vapor form), alongwith the regenerat- 30 to connect valve 30 to vent. This ventingimmediately ing fluid, by way of conduit 9 to drum 10 wherein a switchesvalve 23 to shut oil air supply to valve 14 and portion is condensed bycooling. In the preferred form controllers 20 and 3S, thus shutting downthe regeneraof our invention, superheated vapors of the removed liquidtion circuit as described in the preceding paragraph, and are used asthe regeneration or desorbing uid; accordfurther immediately causesvalve 30 to switch so as to ingly, vapors are Withdrawn from drum 10 byway of 35 connect valve 31 to the vented port of valve 30. Gaugesconduit 11 at a rate controlled by pump 13. Since the 3S and 36, beingconnected to a vent, will now read zero; pump is driven by motor 7, theregeneration iluid rate is since level switch 28 is still transmitting apressure output thus correlated to raw feed gas rate. The regenerationsignal indicative of a normal level, gau-ge 34 will exhibit Huid ispassed by valve 14 to heater 16 wherein it is supera positive reading,valve 29 blocking loss of this signal. heated by heat exchange withfluid in conduit 17, and 40 This combination of gauge readings indicatesa shut-down then passed by way of conduit 11 to the process. Prodof theregeneration system because of high ow rate in uct natural gas liquidsare removed from vessel 24 by conduit 11. way of conduit 25 as theyaccumulate. When for any reason the flow rate of regeneration vapor Solong as ow through conduit 11 is within the prein conduit 11 drops belowthe pre-selected range of transselected range, transmitter 19 passes asignal of 6-12 45 mitter 19, this transmitter produces a signal below 6p.s.i.g. as input to controller 20 which adjusts valve 2 to p.s.i.g.Such a signal does not eifect a change of position further correlate thedrive rate of motor 7. This same of valve 29, but does switch valve 31so as to connect signal also passes to the diaphragms of valves 29 and31, starter 32 to the vented port of Valve 31. This venting positioningthese valves to connect switch 28 to valve 30 immediately switches valve23 to shut off air supply to and valve 30 to starter valve 32respectively. So long as 50 valve 14 and controllers 20 and 38,- thusshutting down the level in tank 24 is below its high level as sensed bythe regeneration circuit as described above. Valves 31 switch 28, thisswitch transmits a l5 p.s.i.g. signal through and 33 block loss ofpressure from .the system including valve 29 to valve 30. In order toput the system into switch 28 and valves 29 and 30. Thus, gauges 34 and35 operation, it is necessary to move starter valve 32 manwill exhibit apositive reading, while gauge 36, being ually so air vfrom the lowerpart passes to the motors 55 connected to vent, will read zero. Thiscombination of of valves 23 and 30. When .this is done pressure fromgauge readings indicates a shut-down of the regeneration switch 28passes through valves 29, 30 and 31 and through system because of lowilow rate in conduit 11. valve 32 when it (valve 32) has been releasedto the The following table summarizes various operating conmotor ofvalve 23, causing it to connect air source 22 to ditions of the system.

TABLE I Operations That Occur When Conditions Become- Normal High Level,Tank 24 High Flow, Conduit 11 Low Flow, Conduit 11 Valve 18...

Transmitter 19, Output Press.

Valve 23 Switch 28, Output Press.

Valve 29.

G auge 35 Gauge 36..

P 6-12 p.s.1.g

14, 38 and 20 from 22... 15 p.s.i.g.

To ByJaSS 3 6-12 p.s.i.g. and then to less than 6 p.s.i.g. 14, 38 and 20to Vent- 15 p.s.1.g 30 to Vent and then 2 32 to Vent. Press.

Press.

Zero.

The invention will now be further illustrated by the following speciiicexample.

Example I A plant for removal of gasoline and water from natural Weclaim:

1. The method of controlling ilow of a huid wherein Isaid fluid passesto a valve zone and thence when said valve zone is in a first positionsaid fluid passes only to a fluid heating zone and when said valve zoneis in a secgas is constructed as shown in the drawing. There are 5 0ndposition said uid passes 0n1y to a nid heating bythree adSorherS, each 5itin diameter by 15 fthigh and pass Zone which comprises maintainingsaid valve Zone in having a nil of 14 ftheight; the upper 7 feet of lilliS SillCa said first position by passing a motive force thereto, measgeland the lower 7 feet of fill is activated carbon. The uring iiow rate ofsaid fluid, producing a signal propor- -silica gel is eicacious forremoval of both gasoline and 10 tional to said flow rate in response toSaid measuring, water from the natural gas, while the activated carbonrein response to said signal being above a first predetermined movesprimarily only gasoline; hence, the ratio of lill of value terminatingsaid motive force so as to cause a first these components will dependupon the concentration of 4indicator zone to exhibit a iirst reading anda second indi- Water in the feed. This plant processes 75,000,000standcator zone to exhibit a rst reading and to cause said Valve ardcubic feet of natural gas per day, and produces as zone to move to .saidsecond position in response to said desorbate a net of 6,600 gallons perday of de-ethanized signal being Ibelow a second predetermined valuetergasoline. minating said motive force so as to cause said irst indica-Compositions CO2 Clrld C3 C4 1104 iC5 1105 CH- Feed, m01 percent 28. 2071.19 .26 .o5 .04 .04 .13 Production, gallons percent 3.10 2.10 5. 456.65 12.40 70. 30

Regeneration of an adsorber yields about G-350 galt-or zone to exhibit asecond reading and said second inlons of liquid hydrocarbon per cycle.About '3S-40 mindicator zone to indicate a lirst reading and to causesaid utes are required to regenerate an adsorber. About 9-10 valve zoneto move to said second position, whereby said million cubic feet per dayof 40G-425 F. vapor is used 35 valve zone effects by-passing lof saidheating zone by said for regeneration, which takes place -at `about 1000p.s.i.g. fluid when said ow rate is outside the range delined by Thefeed is saturated with water at ambient temperature, Said rst and secondpredetermined values and whereby and the treated gas contains less than7 pounds `of water the readings of said first and second indicator zonesindi- .per million cubic feet 0f gas, oate the cause of said by-passing,and passing said fluid t0 Although the adsorption system has beendescribed in 40 Said heating hy-PaSS Zone its presently preferredembodiment wherein a portion of 2- The method of Claim 1 wherein Saidinid iS further the product liquid is heated for use as the regenerationPaSSed to a liquid accumulation Zone further Comprising fluid, it isobvious that an external fluid such as steam, ProducingnSecond Signalonly When the liquid leVel in Said air or nitrogen can be used to effectregeneration of the 1iquid accumulation Zone iS heioW a predeterminedPor' adsorbent through the circuit including conduits 9 and tionthereof, and blocking Said motiVe force So os to Cause 11. In latterinstance Separation 0f product from 45 a third indicator ZOIl t0@Xlllblt a `iilI'St reading and O Cause regeneration fluid can beaccomplished in vessels 10 or Said ValVe Zone to moVe to Said SecondPoSition in the 24. Further, although the control system of theinvena'hSence of Said Second Signal, Wherehy any one of the tion hasbeen described as pneumatic as presently pre- Variables high liquidlevel and iloW outSide Said range ferred, the `system can be hydraulicor electric. In the effects hY-PaSSing of Said heating Zone hy Saidiluid and latter instance, transmitter 19, controller 20, and switchWherehy the combination of readingS of Said niet, Second, 28 `arecommercially available instruments which produce 'and third indicatorZoneS indicates the cauSe of Said a D.C. voltage as output. Sources 21,22 and 37 are lay-namingvoltage supplies. Valves 2, 14, and 18 areactuated by 3- APParatuS for controlling lloW of fluid comprising such.as a solenoid, while valves 23 and 29-31 are SPDT a fluid Source, iluidheating meanS, iirSt conduit meanS switches with the vent connectionsreplaced by ground. Connecting Said fluid Source and said nud heatingmeans, Valve 33 becomes a rectifier, and gauges 29-31 become a by-passaround said iluid heating means, second conduit volt-meters. Onepresently preferred adsorption system means connecting said iluidheating means and said byis described and claimed in co-pendingapplication Serial PaSS ValVe means in Said i'lrSt conduit meanS adaptedt0 No. 172,173, filed February l2, 1962, and a system for p ass fluid tosaid iiuid heating means when in a first posi- -switching such a cyclicadsorption process through the tion and to hY-PaSS 'huid around Saidfluid heating means phases of its cycle is described and claimed in`co-pending when in a Second PoSition, meanS lncludlng a Source of.application Serial NoY 1947572, med May 15, 1962 motive power adaptedtoplace said valve means 1n said Reasonable variation and modication arepossible 'rSt POSltlOn When Connected thereto, means for measurwithinthe scope 1of this disclosure, the drawing, and the mg theow rate .)fSaid md and for producmg a signal appended claims to the invention, theessence of which is p roportlonal to Said lgwhrat rst Copdtrql meanrespon' that there is provided method and apparatus for effecting siveto a presfilected 1g Va u? of sal Signal a 'lpted to dlsconnect saldsource of motive power from said Valve Shutdown of a heatmg fluidSystem-and f or indicating the means and to effect rst readings on a rstand a second Cause of the shui'down wherein a signal ludica/UV? of Olieindicator means, and second control means responsive to of excessivelyhigh and 10W HOW rate of regeneration uld 70 a preselected low value ofsaid signal adapted to discon- -and excessive accumulation ofregeneration fluid effects, neet Said source of motive power from saidValve means upon its transmission to a control zone, the termination andto effect a send reading 0n one of the two of Said of supply of heat tosaid regeneration fluid and in `a furindicator means, ther embodimentthe termination of circulation of said 4. Apparatus of claim 3 whereinsaid second conduit is regeneration fluid. further connected to aliquid-receiving vessel further having a liquid level sensing means onsaid vessel adapted to produce a second signal when the liquid level isbelow a predetermined point in said vessel, and third control meansresponsive to said second signal adapted to connect said -source ofmotive power to said Valve means and to effect a finite reading on athird indicator means.

5. Fluid adsorption control apparatus comprising a lsource of fluidcontaining an adsorbable component, an adsorption vessel, first conduitmeans connecting said source and said adsorption vessel, a supply ofregeneration fluid, connecting conduit means connecting said supply -andsaid vessel, heat supplying means in a by-pass conduit, valve means insaid connecting conduit means and said by-pass conduit adapted to passsaid regeneration fluid through said heat supplying means when in afirst position and to by-pass said regeneration fluid around said heatsupplying means when in a second position, means including a source ofmotive fluid connected to said valve means to apply force thereto tomaintain said valve means in said first position when connecte-d theretoand to allow said valve means to assume said second position whendisconnected therefrom, means for measuring the flow rate of saidregeneration fluid and for producing a signal proportional to said flowrate, first control means responsive to a predetermined high value ofsaid signal adapted to disconnect said source of motive fluid from saidvalve means and to effect a first reading on each of a rst and secondindicator means, and second control means responsive to `a predeterminedlow value of said signal adapted to disconnect said source of motivefluid from said valve means and to effect a second reading on one ofsaid first and second indicator means.

6. Apparatus of claim wherein a liquid level sensing means provided insaid supply of regeneration fluid is Y adapted to produce a secondsignal when the liquid level is below a predetermined point in saidsupply, and third control means responsive to said second signal adaptedto connect said source of motive fluid to said valve means and to changethe reading of a third indicator means.

7. Apparatus of claim 6 further comprising a fluid motor in a by-passconduit in said first conduit means, second valve means in said firstconduit means adapted to pass fluid through said fluid motor when in afirst positiOn and to by-pass fluid around said fluid motor when in asecond position, fluid pump means in said connecting conduit meansdriven by said fluid motor, and means responsive to said first, second,and third control means adapted to move said second valve means from itsfirst position to its second position on occurrence tof any one ofpresence of said predetermined high value, presence of saidpredetermined low value, and absence of said second signal.

8. The method for controlling flow of regeneration fluid in a process,wherein said regeneration fluid is heated prior to its use as such,which comprises heating said regeneration fluid, measuring the flow rateof said regeneration fluid, comparing the measured value with apredetermined desired lflow value range, producing and transmitting afirst signal when said measured value is greater than said range,producing and transmitting a second signal when said measured value isless than said range, terminating the heating of said regeneration fluidin response to either of said transmitted first and second signals, andindicating in an indicating zone which of said first and second signalshas occurred upon occurrence of either of said signals.

`9. The method of claim 8 wherein said regeneration fluid is passed toan accumulation zone prior to said heating further comprising producingand transmitting a third signal when the level of fluid in saidaccumulation zone exceeds a predetermined level, terminating the heatingin response to occurrence of any of said first, second and thirdsignals, and indicating in said indicating zone which of said first,second and third signals has occurred upon occurrence of any of saidsignals.

10. The method of claim 9 wherein there is additionally 8 effected atermination of flow of said regeneration Afluid in response to:occurrence of any of said first, second and third signals.

11. The method of controlling flow of a fluid wherein said fluid passesto a valve zone and thence when said valve zone is in a first positionto a fluid heating zone and when said valve Zone is in a second positionto a fluid heating by-pass zone which comprises further passing saidfluid to a liquid accumulation zone, producing a signal only when theliquid level in said accumulation zone is below a predetermined leveltherein and interrupting said signal when the said liquid level is abovea predetermined level, passing a motive force to said valve zone so asto maintain said valve zone in said first position, when said signal isinterrupted blocking said motive force so as to cause an indicator zoneto exhibit a reading and to cause said valve Zone to move to said secondposition whereby said valve zone effects by-passing of said heating zoneby said fluid and said indicator indicates the cause of said by-passing.

l2. The method of controlling flow of a fluid wherein said fluid passesto a valve Zone and thence when said valve zone is in a first positionsaid fluid passes only to a fluid heating zone and when said valve zoneis in a second position said fluid passes only to a fluid heatingby-pass zone which comprises (1) maintaining a valve Zone in said firstposition by passing a motive force thereto;

(2) measuring flow rate of said fluid;

(3) producing a signal proportional to said flow rate in response tosaid measuring;

(i4) terminating said motive force in response to said signal beingabove a first predetermined value so as to cause (a) a first indicatorzone to exhibit a first read- (b) a second indicator zone to exhibit afirst read- (c) said valve zone to move to said second position wherebysaid valve Zone effects by-passing of said heating Zone by said -fluidwhen said -flow rate is above a first predetermined value and wherebythe readings of said first and second indicator zones indicate the causeof said bypassing;

`(5) and passing said fluid to said heating lay-passing zone uponterminating said motive force.

13. The method of controlling flow of a fluid wherein said fluid passesto a valve zone and thence when said valve zone is in a first positionsaid fluid passes only to a fluid heating Zone and when said valve Zoneis in a second position said -fluid passes only to a fluid heatingbypass zone which comprises:

(1) maintaining a valve zone in said first position by passing a motiveforce thereto;

(2) measuring flow rate of said fluid;

(3) producing a signal proportional to said 4flow rate in response tosaid measuring;

(4) terminating said motive force in response to said signal being belowa first predetermined Value so as to cause (a) a first indicator zone toexhibit a first reading;

(b) a second indicator zone to exhibit a different reading from that ofsaid first indicator zone;

(c) said valve zone to move to said second position whereby said valvezone effects lay-passing of said heating Zone by said fluid when saidflow rate is above a first predetermined value and whereby the readingsof said first and second indicator Zones indicate the cause of said`by-passing;

(5) and passing said fluid to said heating by-pass zone upon terminatingsaid motive force.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Wade.

Shobe 55-165 Parks 55-33 Hobson 210-512 Baker 55-62 Cot-tle 55-21 Maurer55-74 Lamb et a1. 55-33 Young 173-13 Higmans 137-5991 Russell 55-31 Dow55-21 REUBEN FRIEDMAN, Primary Examiner.

8. THE METHOD FOR CONTROLLING FLOW OF REGENERATION FLUID IN A PROCESS,WHEREIN SAID REGENERATION FLUID IS HEATED PRIOR TO ITS USE AS SUCH,WHICH COMPRISES HEATING SAID REGENERATION FLUID, MEASURING THE FLOW RATEOF SAID REGENERATION FLUID, COMPARING THE MEASURED VALUE WITH APREDETERMINED DESIRED FLOW VALUE RANGE, PRODUCING AND TRANSMITTING AFIRST SIGNAL WHEN SAID MEASURED VALUE IS GREATER THAN SAID RANGE,PRODUCING AND TRANSMITTING A SECOND SIGNAL WHEN SAID MEASURED VALUE ISLESS THAN SAID RANGE, TERMINATING THE HEATING OF SAID REGENERATION FLUIDIN RESPONSE